expf(3) - BetterMan

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Range error, overflow	errno is set to ERANGE. An overflow floating-point exception (FE_OVERFLOW) is raised.
Range error, underflow	errno is set to ERANGE. An underflow floating-point exception (FE_UNDERFLOW) is raised.

NAME

exp, expf, expl - base-e exponential function

LIBRARY

Math library (libm, -lm)

SYNOPSIS

bash

#include <math.h>

bash

double exp(double \nx\n);\n
\nfloat expf(float \nx\n);\n
\nlong double expl(long double \nx\n);

expf(), expl():

bash


\n
    _ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
\n
        || /* Since glibc 2.19: */ _DEFAULT_SOURCE
\n
        || /* glibc <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE

DESCRIPTION

These functions return the value of e (the base of natural logarithms) raised to the power of x.

RETURN VALUE

On success, these functions return the exponential value of x.

If x is a NaN, a NaN is returned.

If x is positive infinity, positive infinity is returned.

If x is negative infinity, +0 is returned.

If the result underflows, a range error occurs, and zero is returned.

If the result overflows, a range error occurs, and the functions return +HUGE_VAL, +HUGE_VALF, or +HUGE_VALL, respectively.

ERRORS

See math_error(7) for information on how to determine whether an error has occurred when calling these functions.

The following errors can occur:

Range error, overflow: errno is set to ERANGE. An overflow floating-point exception (FE_OVERFLOW) is raised.
Range error, underflow: errno is set to ERANGE. An underflow floating-point exception (FE_UNDERFLOW) is raised.

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).

Interface	Attribute	Value
exp (), expf (), expl ()	Thread safety	MT-Safe

STANDARDS

C11, POSIX.1-2008.

HISTORY

C99, POSIX.1-2001.

The variant returning double also conforms to SVr4, 4.3BSD, C89.